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The Painfully Misunderstood Distinction between Ultimate and Proximate Explanations

Questionnaires measure conscious needs, not ultimate evolutionary causes.

Steven Reiss criticizes our evolutionary reconceptualization of Maslow’s hierarchy.

Part of Dr. Reiss’s beef is this:

“They … ignored the large bodies of psychometric research independently conducted by Douglas Jackson and myself... I have worked for 15 years and published three book and a dozen or so articles.”

In this, Dr. Reiss is correct, but with all due respect to that body of work, it is largely irrelevant to our arguments. The reason for its irrelevance (and for his annoyance) is linked to a major issue problem we discuss at length in our paper: Major scientific arguments (and minor quibbles, in this case) have been fueled by the failure to distinguish between explanations at different levels of analysis.

Levels of Analysis

What goes on in our minds is influenced by our developmental experiences, and both ongoing phenomenology and psychological development are influenced by evolutionary history. But ultimate evolutionary causes are not represented in our minds. Consider: birds migrate because a mechanism in their brains tells them that the days are getting shorter, not because they think “I am doing this to enhance my inclusive fitness.” Likewise for humans trying to find sexual partners, take care of their children, make friends, get ahead on the job, or show off their creativity. All of these behaviors are ultimately linked to people’s reproductive fitness, but those connections are not represented in their minds.

Reiss makes the following claim: “If evolutionary psychology really implies that parenting is the highest human motive, something is fatally wrong with evolutionary psychology.” Here again a failure to distinguish levels of analysis leads to a problem. Yes, people often think “I don’t want children!” and surely people’s desire to have sex is rarely consciously represented as “I really want to have children to take care of!” But if we keep having sex, we are acting at the behest of mechanisms that, throughout most of evolutionary history, would have produced children. Birth control is a technology that can disconnect the proximate mechanism from its likely evolved function (although those mechanisms still seem to be working all too well in the modern world, if you look at population figures). Once the children are born, though, totally different mechanisms take over (most people, contrary to Reiss’s suggestion, do not desert their infants, and Martin Daly and Margo Wilson (1988) have shown that even when children are deserted by hunter gatherers and modern urbanites, it is not done lightly, but under circumstances of adaptive duress). For a thoughtful set of ideas on the evolutionary psychology of parenting, and the discrepancy between different levels of analysis, see Sonja Lyubomirsky’s post (cited below).

If Dr. Reiss is feeling a bit of moral righteousness about our not paying sufficient attention to other people’s work, I can appreciate and empathize. Every time I publish a paper, reviewers remind me that there’s a lot of research out there I don’t know, read once and forgot about, or simply deemed irrelevant to the current paper. When I review a paper myself, I try to remind my know-it-all reviewer self of those experiences. In the case of the current argument, though, our recently published paper (the very one about which Dr. Reiss is talking) addresses at great length why research on people’s conscious needs is not relevant to the question of ultimate evolutionary causation.

So although our reconceptualization of Maslow’s pyramid will not likely produce a questionnaire to replace the work he and Doug Jackson have done on this topic, our theory has generated a host of empirical findings, some cited below. And yes, the theory is also generating a lot of new ideas yet to be tested. But Steve, that’s how science works—theory PLUS empirical research, not just one OR the other.

Related posts

Why kids don’t make us happy. Sonja Lyubomirsky.

Rebuilding Maslow’s pyramid on an evolutionary foundation.

Self-actualization dethroned: Did we murder Maslow’s sacred cow?

Evolutionary Maslow Unscientific. Steven Reiss's criticism.

A few empirical papers spawned by this theoretical approach:

Becker, D.V., Anderson, U.S., Neuberg, S.L., Maner, J.K., Shapiro, J.R., Ackerman, J.M., Schaller, M., & Kenrick, D.T. (2010). More memory bang for the attentional buck: Self-protection goals enhance encoding efficiency for potentially threatening males. Social Psychological and Personality Science, 1, 182-189.

Griskevicius, V., Cialdini, R.B., & Kenrick, D.T. (2006). Peacocks, Picasso, and parental investment: The effects of romantic motives on creativity. Journal of Personality and Social Psychology, 91, 63-76.

Griskevicius, V., Goldstein, N.J., Mortensen, C.R., Sundie, J.M., Cialdini, R.B., & Kenrick, D.T. (2009). Fear and loving in Las Vegas: Evolution, emotion, and persuasion. Journal of Marketing Research, 46, 384–395.

Griskevicius, V., Goldstein, N., Mortensen, C., Cialdini, R.B., & Kenrick, D.T. (2006). Going along versus going alone: When fundamental motives facilitate strategic (non)conformity. Journal of Personality and Social Psychology, 91, 281–294

Maner, J.K., Kenrick, D. T., Becker, D.V., Robertson, T.E., Hofer, B., Neuberg, S.L., Delton, A.W., Butner, J., & Schaller, M. (2005). Functional Projection: How Fundamental Social Motives Can Bias Interpersonal Perception. Journal of Personality and Social Psychology, 88, 63-78.

Maner, J.K., DeWall, C.N., Baumeister, R.F., & Schaller, M. (2007). Does social exclusion motivate interpersonal reconnection? Resolving the ‘‘porcupine problem.’’ Journal of Personality and Social Psychology, 92, 42–55.

Schaller, M., Park, J.H., & Mueller, A. (2003). Fear of the dark: Interactive effects of beliefs about danger and ambient darkness on ethnic stereotypes. Personality and Social Psychology Bulletin, 29, 637–649.

Sundie, J.M., Kenrick, D.T., Griskevicius, V., Tybur, J., Vohs, K., & Beal, D.J. (in press). Peacocks, Porsches, and Thorsten Veblen: Conspicuous consumption as a sexual signaling system. Journal of Personality & Social Psychology.

Some papers offering related, but yet-to-be-fully-tested theoretical ideas:

Ackerman, J.M., & Kenrick, D.T. (2008). The costs of benefits: Help refusals highlight key trade-offs of social life. Personality & Social Psychology Review, 12, 118–140.

Kenrick, D.T., Li, N.P., & Butner, J. (2003). Dynamical evolutionary psychology: Individual decision-rules and emergent social norms. Psychological Review, 110, 3–28.


Daly, M., & Wilson, M. (1988). Homicide. New York: Aldine de Gruyter.

Kenrick, D.T., Griskevicius, V., Neuberg, S.L., & Schaller, M. (2010). Renovating the pyramid of needs: Contemporary extensions built upon ancient foundations. Perspectives on Psychological Science, 5, 292–314

Reiss, S. (2004). Multifaceted Nature of Intrinsic Motivation: The Theory of 16 Basic Desires. Review of General Psychology, 8, 179- 193.

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